Cannot change resolution on Studio 17?

This is by design - rather than produce a fuzzy image at lower resolution, the driver cuts the screen size.  You will not be pleased by running a WUXGA panel at WSXGA+ resolution - if you need that resolution, return the system and order the lower resolution panel.  Notebook LCDs are designed for their native resolution and will look poor at anything below that.

Have you tried installing the new Dell ATI Catalyst drivers for the Studio 1535 and 1735.  They add a few more missing display resolutions and improve dual external monitor support.  It also fixes all (including 1440 x 900) but one of the scaling errors (1920 x 1080) between 1280 x 1024 and 1920 x 1200. It should work for all version of Vista.

Studio ATI Drivers

If you want tro see how 1440 x 900 looks in like full screen, then you need to click the above Dell link.

I also have a Studio 1735, barely a week old, Vista Ultimate, native resolution 1920x1200, with exactly the same problem. Couldn't believe it!!! Even my 5 year old Inspiron 8500 can display all these resolutions.
I tried the update above. It failed part way through with the message:-

Could not load file or assembly 'MOM.Implementation, Version=2.0.3182.4658, Culture=neutral, PublicKeyToken=90ba9c70f846762e' or one of its dependencies. The system cannot find the file specified.

As the version of the driver had updated I thought it worth a whirl. Yes it will display 1440x900, but hasn't corrected the problem of the DPI set to anything but the default causing Windows Explorer max width to be incorrect, unless you also set XP style.
The Catalyst Control Centre errored on opening and everytime I restarted I got that message, so I gave up and System Restore seems to have got me back safely.

Any ideas what to do about the above error? And where do I report this update failure? I did keep the log.

If your Dell 1735 is less than a week old, then why are you trying to update the ATI 3650 Catalyst driver with an upgrade from October 26th, 2008?  It should have come with the lastest drivers if you bought it recently from Dell.:emotion-40:

In any event, you can try uinstalling the Ati Catalyst software and removing all the drivers from device manager, making sure you click the button to delete the current drivers.  Clean the registery with your favorite registry cleaner to remove dead links, Install the orginal Catalyst software drivers, which you can find from the same location as the upgrade, and then install the updated overtop of that.  :emotion-5:

My Dell 1735 came with an earlier driver than this update. The instructions on installing don't mention uninstalling first as you have, so thanks for that. Dell phone support in the meantime has now fixed this black border problem - see my later post at Studio 17 Vista Ultimate with AMD ATI Mobility Radeon HD
However I should mention their first attempt, after uninstalling the drivers, resulted in having to reinstall the backup image.

Dell Forums is just great and has solved many many problems for me in the past. Thanks everyone for your help.

If your Dell 1735 is less than a week old, then why are you trying to update the ATI 3650 Catalyst driver with an upgrade from October 26th, 2008?  It should have come with the lastest drivers if you bought it recently from Dell.:emotion-40:

As proven by the post above this... the version of drivers Dell systems should have installed, and what they actually have installed, are two completely different things :emotion-55:

It's likely, that the installed drivers are the latest ones available on the website, and Dell are infamous for not keeping (what many consider to be) important drivers up-to-date on the website (i.e. graphics and audio), so it's only fair to assume their systems won't have them either :emotion-40:

And I they do ship systems with newer drivers than are offered on the website, that only emphasises how poor they are at updating the website drivers.

Thankfully... suitable graphics and audio drivers at least, can be found from alternative sources, but if they're available, owners shouldn't have to look for/get them elsewhere :emotion-43: